docs: def valid_mitemp_mac(mac, pat=re.compile(r"4C:65:A8:[0-9A-F]{2}:[0-9A-F]{2}:[0-9A-F]{2}")):
      """Check for valid mac adresses."""
      if not pat.match(mac.upper()):
          raise argparse.ArgumentTypeError('The MAC address "{}" seems to be in the wrong format'.format(mac))
      return mac